INTRODUCTION :
Pipeline system mean all parts of physical facilities through which gas trasnported, include pipe, valve, appurtenances attached to pipe, compressor, unit, metering station, regulator station, deliverability and holder. Managing the integrity of gas pipeline system is the primary goal of every system operator to continue providing safe and reliable delivery of natureal gas to their customer without adverse effect on employees, the public, customer or the enviroment. Incident – free operation to become goal of pipeline insdustry. ASME B31.8 code will allow pipeline operators to move close to that goal.